This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), is a global infectious disease emergency. A major hurdle in combating TB is the fact Mtb is able to persist for long periods of time in host tissues, in a quiescent state. These bacilli are able to reactivate and cause pulmonary TB, when the immune system is compromised. Hence, a complete understanding of TB latency and reactivation is required for the effective control of TB. NHLBI has funded Drs Karakousis and Bader and colleagues at the Johns Hopkins School of Medicine to study tuberculosis latency and reactivation from the perspective of the pathogen in a number of experimental animal models. In a subcontract to the TNPRC have been entrusted with the task of performing these experiments in nonhuman primates.